1. Field of the Invention
This invention relates to a respirator mask for a compressed air breathing apparatus with a lung machine controlled by a control membrane and an expiratory valve with an air outlet.
2. Background Art
Respirator masks, when combined with a compressed air respirator, are typically operated with a lung machine that is connected to the facepiece by a screwed or plug-in connection. The air supply from a pressure reducer via a medium-pressure line is controlled by a control membrane operated by the mask wearer's inhaling that mechanically acts on a control valve which in turn releases the medium-pressure line as required. The thin membrane made of an elastic material is of course highly sensitive to environmental conditions involving extreme temperatures and aggressive media. The functioning of the membrane may be impaired, for example, by reduced elasticity in low temperatures which adversely affects resistance to breathing and sensitivity, or if the membrane material is penetrated, destroyed, or severely mechanically damaged by aggressive gases such as hydrogen sulfide or phosgene.